Description of Research Expertise

RESEARCH INTERESTS: Understanding how the structure, biophysical properties, and synaptic connections of a neuron influence its signal processing function within the surrounding neural circuit.

RESEARCH TECHNIQUES: Analysis of the role of synaptic and biophyical properties, morphology, and noise in a neural circuit's performance. Electrophysiological recordings. Computer simulation of neural circuitry. Ideal observer analysis of neural circuit performance.

RESEARCH SUMMARY: My laboratory studies how retinal circuitry processes visual signals. We analyze what is known about a circuit, construct a biophysically realistic model of it, and through simulation attempt to reconcile the circuit's known physiological properties with the function of its neural components. This allows us to suggest a functional interpretation for biophysical features such as dendritic branching, density of voltage-gated membrane channels, and specific location, strength, and properties of synaptic inputs. Including the noise properties of membrane channels and synaptic vesicle release, we generate realistic noise properties that we compare directly with recordings from live neurons. We currently study 4 circuits: 1) the cone photoreceptor to horizontal cell network, 2) the pathway from rod photoreceptors to ganglion cells used during dark adaptation, 3) the brisk-transient (alpha) ganglion cell, its spike generator, and its presynaptic circuitry, and 4) the direction-selective ganglion cell and the starburst amacrine network that shapes its responses.